Vader doesn't come close to Joker, honestly. Anton Chigurh, Hans Landa, and Hannibal Lecter were also better villains. Acting is important and the 4 of them beat Vader in that regard. His mask did not allow for facial expressions, you can make that as an excuse, but that's what he is. Also, I found Norman Bates shockingly unterrifying.

I agree those are all amazing villains but Vader just so captures the archetype. There's something so elemental about the soulless mask and that terrifying, menacing voice. To me the lack of seeing his face is part of the point and adds to the mystique.

I do agree that I would put Anton Chigurh and Hannibal Lecter in my top ten, but they would be above the Joker...and probably below Vader. I loved Hans Landa but I'm not sure how much that movie will grow on me over time, I love it now but I dunno if it's ever going to equal Pulp Fiction or Reservoir Dogs for me...

I admit characters like Chigurh and Lecter, and indeed the Joker, are much more complex characters, thematically, than Vader, who is something of a cliche, but that's kind of the point, he's supposed to be like a classic villain from a melodrama. He desires power and control. He doesn't represent an abstract concept like nihilism or anarchy, he's a very concrete villain.